Burglar -alarm



H. R.v ROBBINS.

Burglar Alarm.

Patented Oct. 19, 1858.

`UNITED STATE-)#SETEN T OFFICE.

HENRIr R. ROBBINS, 0F BALTIMORE, MARYLAND.

BURG'LAR-ALARM.

Specification of Letters Patent No. 21,849, dated October 19, 1858.

T o all whom it 'may concern:

Be it known that I, HENRY R. RoBiNs, of the city of Baltimore and Stateof Maryland, have invented a new and useful Improvement inBurglar-Alarms; and I do hereby declare that the following is a full,clear, and exact description of the same, reference being had to theaccompanying drawings, forming a part of this specification, in which-Figure l, is a front view of a door with my improved burglar alarmattached to it. Fig. 2, is an edge view of the same.

Similar letters of reference in each of the several figures indicatecorresponding parts.

The nature of my invention consists in the manner hereinafter specifiedof combining and arranging relatively to each other on a door and doorframe, the alarm movement, cap-nipple, exploding spring hammer and stopor set pin, whereby simultaneously with the operation of setting thehammer so as to explode a cap when the door is opened the verge of thealarm movement is caused te lock the verge wheel and thus prevent therunning down of the spring and simultaneously with the opening of thedoor and the explosion of the cap, the verge wheel is unlocked and thealarm movement caused to give a continuous alarm.

To enable others, skilled in the art, to make and use my invention, Iwill proceed to describe its construction and operation.

The alarm movement which I adopt is very similar to an ordinary clockmovement as will be evident from the drawing and therefore need not beparticularly described. This movement A, I3, C, M, N, is attached to aplate F, which is screwed to the top of a door G, on the inside of asleeping room, or other place, as represented.

H, is the cap exploding hammer which I employ in connection with thealarm movement. This hammer is pivoted by its handle to the plate F, insuch a position relatively to the crack which exists between the top ofthe door and the door frame G1 that it shall stand across said crackwhen set for operation and the door is closed.

I, is a link attached to the top part of the hammer.

J, is a stop or set pin attached to the top piece of the door trame. Onthis pin the perforated end of the link I, catches when the door isclosed and the hammer setfor operation as shown in black, said link andpin serving to hold the hammer in operative position.

K, is the cap nipple, it is arranged under the hammer and receives anexplosive cap, as represented.

L, is a wire connecting the cap exploding hammer with the verge A, ofthe alarm movement. lThis wire should have no slack so that when thehammer H, is raised and set as shown in black, the verge shall be causedto lock the verge wheel B, and thus hold the spring C, from running downuntil the proper time for sounding the alarm arrives.

YWith the above arrangement and combination, it will be evident that ifthe spring C, is wound up, the verge wheel locked, and the cap explodinghammer set, when the door is opened, the cap exploding hammer H, willdescend and explode the cap and thus by its descent will, through thewire L, operate the verge and thereby unlock the alarm movement andallow it to operate the hammer M, of the alarm bell N, with a quickcontinuous movement.

It is very important to have an alarm capable of producing a suddenexplosive sound, and then to give a continuous alarm by means of a bell,as very many persons cannot be aroused from a deep slumber by 4the soundof a bell.` while most persons, will be instantly aroused by the suddenexplosion of' a cap or pistol. Hence itis, that in several instances,pistols or small cannons have been used in connection with locks,holdfasts, &c.

My invention differs from, and is superior to, the devices before usedin its simplicity and utility, it being readily attached to any door andcosting very little more than an ordinary cheap clock movement, andserving to give a sudden start to the sleeper When a burglar enters theroom, and then ploding spring hammer H, and stop or set J keepngmup aContinuous alarm until he s pin J for the purpose set forth.

fully aroused and made aware of his danger. The above specification ofmy improve- What I claim as my invention and desire ment in burglaralarms signed by me this to secure by Letters Patent, s 16th day ofSeptember, 1858.

The manner herein speced of combining H. R. ROBBINS. and arrangingrelatively to each other on a lVtnesses: door Gr and door frame G1 orother. struc- WVM. L. KEELER, ture, the alarm movement, cap nipple K,eX- E. F ERD MAY.

